A data reception part 101 for receiving data, a data transmission determination part 102 for determining where the data should be transmitted according to, at least, the address written in the data, a data transmission part 103 for transmitting data, and a transmission band management part 104 for managing information on a transmission band. And an information drop method is characterized by having, as an input, contents to which the priority of the contents is added and processing where the contents are divided into packets of the Internet protocol and the priority of the contents is made to correspond to a priority field of packets of the Internet protocol, and said packets to which the priority is added are classified into drop classes having at least two or more different drop probabilities and said packets are dropped in accordance with the network load.